Dental chair.



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*QQ Q 3 Patented Mar. 26, |90l. E. M. FREDERICKS.

DENTAL CHAIR.

(Applicaticn led Apr. 10. 1899.;

` 2 Sheets-Sheet l.

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N0. 670,773. Patented Mar. 26, |90I. E. M. FREDEBICKS.

DENTAL CHAIR.

[Application filed Apr. 10, 1899. (LND HOUBL) 2 Sheets-Sheefz.

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UNITED STATES PATENT OFFICE. f i

ENOCI-I M. FREDERICKS, OF CHICAGO, ILLINOIS.

DENTALcHAlR.

SPECIFICATION forming part Of Letters Patent NO. 670,773, dated March 26, 1901. Application filed April 10, 1899. Serial No. 712,417. (No model.)

T all whom it may concern:

Beit known that I, ENOCH M. FREDERICKS, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Dental Chairs, of which the following is a specification.

This invention relates to certain improvements in that class of dental chairs in which a liquid column is employed to raise the seat or body thereof; and it consists in certain peculiarities of the construction, novel arrangement,and operation of the various parts thereof, as will be hereinafter more fully set forth and speciiically claimed.

The principal object of my present invention is to provide simple and efficient means to more rigidly and firmly support the body of the chair than usual heretofore, whereby all lateral movement thereof is prevented.

Another object is to provide means for raising and lowering the seat or body that will permit of a large range of movement.

" In order to enable others skilled in the art to'which my invention pertains to make and use the same, I will now proceed to describe it,referring to the accompanying drawings, in which- Figure l is a vertical sectional view, partly in elevation, taken on the plane 2 2 of Fig. 2, showing the supporting mechanism for the chair-body. Fig. 2 is a plan sectional view taken on line 3 3 of Fig. l with the mechanisms for operating the pump andrelease-valve omitted. Fig. 3 is a similar View, partly in elevation, of a part of the lower portion of the chair, showing the mechanisms for operating the pump and release-valve. Fig. 4 is a central vertical sectional view taken on line 5 5 of Fig. 2, showing the supporting and adjusting mechanism for the chair-body. Fig. 5 is a fragmental vertical sectional View taken on line 6 6 of Fig. 2. Fig. 6 is a similar view taken on line 7 7 of Fig. 2, and Fig. 7 is a perspective view of a portion of one of the supporting-pieces or plungers of the chair-body.

Similar letters refer to like parts throughout the different views of the drawings.

A represents the base or pedestal ot' the chair, which, as shown Vin the drawings, is

preferably cylindrical in form and provided with a cylindrical cavity, in which is located a portion of a revoluble cylinder A', whose outer surface is provided about its middle with an annular flange a to rest on the upper end of the pedestal or base. The upper portion of the revoluble or supporting cylinder A' is provided internally with an annular rib or flange a for strengthening the same, above which is located on rthe said cylinder a cover A2, having au opening a2 for the reception and operation of one of the body-supporting pieces or plungers, as will be presently explained. Within the lower portion of the cylinder A is located a vertical partition as, which, together with the wall of said cylinder, forms a reservoir A3 for the liquid a, which may be of any suitable kind. The upper portion of the supporting or revolving cylinder Ais formed or provided on its inner'surface with two enlarged portions or parts B and B', which are located opposite each other, as is clearly shown in Fig. 2 of the drawings, and are each provided with an angular way or groove b and a similarlyshaped recess or depression b to receive and retain a quantity of Babbitt metal b2 or other antifriction material. The wayshor grooves b are coextensive with said enlargements, and

the recesses b are simply depressions in the` walls of the ways or grooves. Passing through the enlarged portion B are a series of screws 3, whose inner ends rest against an adjusting-plate b4, which is movably embedded in the metal b2, located within the recess of the enlargement B, the face of which plate rests against the outer supporting-piece or plunger C of the chair-body. To one side of the enlargement B' the revoluble cylinder is provided on its inner surface with a lug or projection b5, against which a suitable projection c on the outer plunger C will strike when said plunger is raised to its uppermost position. The projection c is preferably a screw which engages the lower portion, of the plunger C, access to which screw may be had through an opening a5 in the lower portion of the cylinder A when it is desired to remove the screw c in order that the plunger C may also be removed. The plunger C, as

vIO!) shown in Fig. 2 of the drawings, is substantially of an elliptic'lanceolate form in crosssection and has both of its ends open and is provided at each of its apices, near its upper end, with a recess c (see Fig. 7,) to receive and retain a quantity of Babbitt or other suitable antifriction metal b2. rIhe recesses c are formed, in thickened or enlarged portions c2 on'the inner surface of the plunger, which extend from the upper end thereof downwardly a short distance on each side of the apices of said plunger, as is clearly shown in Figs. 2 and 7 of the drawings, in which figy piece C, which is substantially of an elliptic lanceolate form and has thickened or enlarged parts c6 on its outer surface at each side of its apices, which enlargements extend from near the top of the said plunger or supportingpiece to about its bottom and form bearingsurfaces for said piece or plunger. By pro- Viding the plungers C and C with the thickened or enlarged portions on their meeting surfaces at their apices it is apparent that the bearing-surfaces thereof are reduced to said portions, and'while I have shown both plungers with enlarged or thickened portions, yet it is apparent that one only may be so formed and the saine result attained. The outer enlargements or thickened portions c3 on the outer plunger may sometimes be omitted, as is evident. The upper portion ofthe plunger or supporting-piece C is provided with anannularshoulder c7, on ,which may resta castingD, to which a chair-body of the ordinary or any preferred construction maybe secured and supported. The lower portion of the plunger C' is provided with a projection o8, access to which may be had through the opening o9 in the plunger C, and which projection is usuallyin the form ofa screw engaging the plunger and is employed to contact with the annular flange C10 on the inner surface of the outer plunger, and thus prevent further upward movement of the inner plunger. Passing through the top of the plunger C is a piston-rod E, whose upper portion is screwthreaded, as at e, to engage the screw-threaded opening in the top of the plunger and also a locking-nut e on its upper end. While I prefer to use this means of securing the piston-rod to the plunger C', yet I may secure it in any other suitable manner. On the lower end of the rod E is a piston E', which its closely within the cylinder E2, whose lower end issecured to the lower portion of the revoluble cylinder A and usually by being screwed into a boss e2 on the bottom thereof. Surrounding the cylinder E2, at about its middle portion, is a cup E3, whose upper end is open to receive any of the liquid which shown in Figs. l and 2 of the drawings, and

has a port d communicating with a suctionvalve casing G,'situated in the lower portion of the reservoir. Seated in the bottom of the pump-cylinder F is a valve G' of the ordinary or preferred construction, which controls the iiow of liquid from the pump-cylinder to the cylinder E2, or raising or lowering cylinder. Communicating with the lower portion of the cylinder E2 through a port d2 is a release-valve casing H, which is located in the lower portion of the revoluble cylinder and usually within the res,ervoir,as shown, the construction and operation of which will presently be explained in detail.

Within the pump-cylinder F is located a piston F', whose lower portion may be provided with a series of annular grooves f to receive a quantity of the liquid and tocause it to act as a packing for saidpiston. Pivotally secured at one of its ends to the upper end of the piston F is a piston rod or bar F2, whose other end is pivotally secured to an arm F3, xed on a shaft f', which has itsy f bearings in the revoluble cylinder A and is furnished at its outer end with a foot-lever f2 to be used for operating the pump. Conneet-ed at one of its ends to the piston-rod or bar F2 is a springf, whose other end is secured to a suitable support on the revoluble cylinder, and which spring is employed to retract the piston F' of the pump.

As shown in Fig. l of the drawings, the release-valve consists of a casing H, which has an outlet-port h and a flaring seat for the beveled portion of the pin-valve, and is secured in a suitable opening in the .bottom of the revoluble cylinder A', and, as before stated, communicates through the port (Z2 with the cylinder vE2 in its lower portion. Secured on the valve-stem h4 is a piston, between which and the upper end of the valvecasing is located a spring h6 to normally hold the Valve in a closed position. Secured at one of its ends to the upper end of the valvestem is a rod h7,whose other end is connected to a shaft g, having its bearings in the revo- IOO IIO

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luble cylinder A', and to the outer end of which is secured a foot-lever g', which is providedwith a projection g2, adapted to contact with a screw g3, secured in a suitable lug or projection g4, on the outer surface of the revoluble cylinder, and which screw is employed to regulate the stroke of the lever g' so as to increase ordiminish the flow of liquid through the release-valve- Passing through the pedestal or base A is a set-screw l, whose inner end will impinge the outer surface of the revoluble cylinder A and prevent the rotary or other movement thereof when desired.

From the foregoing and byreference to the i drawings it will be readily understood and seen that by operating the foot-lever]c2 the piston F of .the pump will be forced up and down, thus causing the liquid a4 to be drawn through the valve G and from thence through the port d into the pump-cylinder, and from thence through the port d into the cylinder E2, which will cause the piston-rod E located therein'to rise and carryr with it the plunger C until the projection es on its lower portion strikes the flange 010 on the plunger C, when thelatrer will be raised to the desired height or until the projection c thereon strikes the lug b5 on the revoluble cylinder, which will prevent the further upward movement of the plungers. lVhen it is desired to lower the chair-body, the foot of the operator may be placed on the lever g, when by pressing said lever downward the release valve will be raised or opened, thus allowing the liquid to escape from the cylinder-E2 into the reservoir. The flow of the liquid through the escapevalve maybe regulated so as to lower the chair-body rapidly or slowly by setting the screw g3,with which the projection g2 of thelever g contacts, at the proper point. By employing the plungers or supporting-pieces for the chair-body of the form and construction above set forth with angular bearing-surfaces it is apparent that said surfaces thereof are greatly red uced,thus reducing the amount of friction and at the same time providing a supporting means which will prevent any lateral movement of the chair-body or other movement thereof except when desired. By using the Babbitt metal or other antifriction metal b2 in the recesses of the guideways or grooves b of the enlargements B and B on the cylinder A' andin the recesses of the outer plunger it is apparent that said parts will be prevented sticking together, yet will be firmly and securely guided and held in place. Should the meeting surfaces of the two plungers and the meeting surfaces of the outer plunger and enlargements B and B become worn by continuous use, so as to permit of any lateral movement of the plungers, the

4plates bl and c5 may be adjusted against the outer and inner plunger, respectively, by means of the screws h3 and c4, which impinge said plates, as above mentioned.

Having thus fully described myinvention,

what l claim as new, and desire to secure by Letters Patent, is-

l. The combination of two pieces or plungers telescoping with one another and each being substantially of an elliptic lanceolate form in crossfsection, with a piece having guideways for the reception and operation of the outer piece or plunger, antifrction metal located between said guideways and the bearing-surfaces of the outer plunger, a plate located in one of said guideways, and means for adjusting said plate against the outer plunger, substantially as described.

, 2. The combination of two pieces or plungers telescoping with each other and each having angular bearing portions, with a piece having angular guideways for the reception and operations of the bearing portions of the outer piece or plunger, and having a recess in each of its guideways anntifriction material located in each of said recesses, and an adjustable plate located in one of said recesses, substantially as described.

3. The combination of two pieces or plun gers telescoping with each other and each having angular bearing portions, the bearing portions of the outer plunger being provided each with a recess, with an adjustable plate located between the bearing-surfaces of the two plun gers, substantially as described.

4. The combination of a cylinder having on its inner surface vertical guideways, with two pieces or plungers telescoping with one another and having angular bearing portions,

the outer piece or plunger being located in the guideways of the cylinder, an adjustable plate located between the surface of one of the guideways and the surface of one of the bearing portions of the outer plunger andan adjustable plate located between the bearingsurfaces of the pieces or plungers, substantially as described.

5. The combination of a cylinder having 011 its inner surface vertical guideways, with two pieces or plungers telescoping with one another and having angular bearing portions, the outer piece or plunger being located in the guideways of the cylinder, an adjustable plate located between the surface of one of IIO the guideways of the cylinder and the surface of one of the bearing portions of the outer plunger, an adjustable plate located between the bearing-surfaces of the pieces or pl ungers, a piston connected to the upper portion of the inner plunger and means to raise said piston, substantially as described,

6. The combination of a cylinder having ou its inner surface vertical guideways,each provided with a recess, with two pieces or plungers telescoping with one another and having angular' bearing portions, the outer piece or plunger being located in the guideways of the cylinder and having on the inner surface of each of its bearing portions a recess, antifriction material located in the recesses of the guideways and of the outer plunger, an pieces or plungers, substantially' as deadjusteble plate located between the surface scribed. of one of the guideweysof the cylinder andv the surface of one of the bearing portions of ENOCH M FREDERICKS 5 the outer plunger, and an adjustable kplate Witnesses:

located between the bearing-surfaces of the CHAS. C. TILLMAN,

pieces or plungers, and means to .raise said E. A. DUGGAN. 

